Process for making acetyl-cellulose plastic compounds.



UNITED STATES PATENT OFFICE.

' WILLIAM G. LINDSAY, OF CALDWELL, NEW JERSEY, ASSIGNOR TO THE CELLULOID COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PROCESS FOR MAKING ACETYL-CELLULQSE PLASTIC COM POUNDS.

No Drawing.

To all whom it nwy concern;

- Be it known that I, WILLIAM G. LINDSAY, a citizen of the United States, residing in Caldwell, county of Essex, State of New Jersey, have invented certain new and useful Improvements in-Processes for Making Acetyl-Cellulose Plastic Compounds, of which the following is a specification.

The various compositions to which the present invention relates are employed in the arts, generally as imitations of natural substances, sometimes in their original finished form With or without incorporated colors and other inert substances, and sometimes as films which are used for photographic and other purposes.

Although the final or useful form of the different compounds of acetyl cellulose is that of a solid material, the different proc: esses of conversion ihto this final solid form involve, as is Well understood, the employment of solutions or mixtures of varying consistency as to plasticity, stiffness, or fluidity, depending generally upon the proportion and kind of solvent used to the amount of the original baIse-acetyl cellulose.

It has been known for many years that camphor and. ethyl alcohol in admixture form a solvent for nitrocellulose in the cold or at room temperature, and also that the camphor can be mixed-with the nitrocellulose and that the subsequent addition of ethyl alcohol causes solution-or conversion of the nitrocellulose. I'have found, however, that when that process is applied to acetyl cellulose no solvent action takes place and the object of my invention Was to find substances which, when added to acetyl cellulose would exert a solvent action upon .he cellulose and produce a plastic mass, and

also to find substances that can be added to the mixture so as to render the final product substantially non-inflammable.

In the course of my experiments I have discovered that a mixture of either tetrachlorethyl acetanilid or trichlormethyl acetanilid, or a mixture of the two, in conjunction with methyl alcohol in substantially equal proportions of the solids and the alcohol, will convert that variety of acetyl cellulose Which is soluble in acetone into a plastic mass or compound capable of being worked, as in the case of the nitrocellulose-camphor plastic art. I have further found that Specification of Letters Patent.

Patented Oct. 15, 1912.

Application filed November 27,1911. Serial No. 662,745.

triphenylphosphate or tricresylphosphate, or a substance similar to these two, in proper admixture, will not prevent the solvent action of the other ingredients named'upon the acetyl cellulose, and that their addition serves torender the resulting product substantially non inflammable.

As one example of practlsing my invention, I take 100' parts of acetyl cellulose of the acetone soluble variety and mix it with from 15 to 25 parts of either tetrachlorethyl 'acetanilid or trichlormethyl acctanilid and 15' to 25 parts of-either triphenylphosphate or tricresylphbsphate, and stir until the mixture is approximately homogeneous. I then add, by sprinkling or otherwise, from 40 to 50 parts of methyl alcohol and allow the mass to soak or macerate at room temperature in a closed vessel until gelatinization of the mass has taken place. The compound can then be worked upon the rolls or ina heated press or mold, as is usual in the nitrocellulose-mam hor art. The block or cake thusproduce can be cut into sheets and dried in the usual way; or, if desired, the composition may be molded in a suitable heated mold into the final shape desired. If it should be desired to' use smaller proportions of the solids, as may be necessary in order to produce a material havin a high degree of hardness or solidity, and if this decrease in the amount of solids used results in a mixture having apparently little or no solvent action in the cold, gelatinization may- -be brought about by heating a mixturecontaming as low as 10 partsof the solid in-- gredients of the solvent to 100 parts of the acetyl cellulose (acetone soluble variety) and 50 or more parts of methyl alcohol. As to temperature, the most suitable one is easily ascertained by a few tests and depends upon the consistency desired. Placing the mixture in a suitable closed vessel and subjecting it to the temperature of a boiling water bath or a steam bath of- 100? C., gives satisfactory results.

It must be noted that as the proportion of methyl alcohol to the solid ingredient or ingredients of the solvcnt'incrohses beyond that of 1 to 1, the solvent action in .the cold decreases rapidly, but it may be restored by the application of heat and still further promoted by the joint application of heat and pressure. A proportion of 10 parts of the solid ingredient or ingredients of the 1. The process I so solvent to 80 parts of methyl alcohol will produce a comparatively thin solution with the aid of heat and pressure. Thls may be useful in cases where a filtration can bedone under the influence of heat and pressure. 7

A solution thus produced will solidify when cold, but it is best to remove the excess of methyl alcohol byevaporation down to, sav,

equal parts of=solids and methyl alcohol" before cooling.

"It will lief-understood that slight variations in the proportions of the ingredients of my. new solvents and their proportion to j the acetyl cellulose would not be a departure from thespirit of my invention, and it will likewise be understood by those skilled in the art that it is permissible to mix the acetyl cellulose and the ingredients of my new solvents in any order desired so long as solvent action is not permitted to take place so soon asto prevent incorporation of the cellulose with the ingredients of the solvent. It will also be understood that coloring matters and other inert substances can also be incorporated if desired. 'yl -laving thus described I claim is acetyl cellulose which consists in dissolving or converting an acetyl cellulose that is'soluble in acetone, by theuse of one'or more members of the hereinbefore-specified group 'of acetanilids -(tetrachlorethyl acetanilid, trichlormethyl acetanilid) and one or more my invention, What of dissolving or converting of the hereinbe f ore specified group of phosphates (triphenylphosphate, tricresylphos phate) together with methyl alcohol, substantially .as described.

2. The process of dissolving or converting acetyl cellulose which consists in dissolving or co'nierting an acetyl cellulose that is solable in acetone, by (1) mixing'said acetyl acetyl cellulose which consists in dissolving or converting an acetyl cellulose that is soluble in acetone, by (1) mixing said acetyl cellulose with one or more of the hereinbefore-specified group of acetanilids (tetrachlorethyl acetanilid, tric'hli'irinethyl acetanilid) and one or more of the her'einbeforespecified group of phosphates (triphenylphosphate, tricresylphosphate), and coloring matters or other inert substances; and (2) adding methyl alcohol to the mixture, substantially as described. I

WILLIAM G. LINDSAYL Witnesses: i

J. E. HINDON HYDE, ill/ ABEL DENTON. 

